Relativity Guide Relativity Facts Different Views Science Topics Home Page Email GM Arts Einstein's Relativity - Different Views The original intention of my Einstein Relativity web pages was to explain without scientific jargon what happens and what it looks like when you embark on very high speed travel.   What happens is clearly defined in Einstein's Formulas, and rarely disputed.   What it would look like has raised different opinions from people who have considered the scenario. Before I get into the different possibilities, consider that observers judge distance by their perception of size (absolute and relative), colour depth, and possibly other cues.   For the sake of this discussion, I will assume that Bob can differentiate between different distances to the star. If you haven't already, you might want to review the scenario.   Briefly, this discussion relates to a star 8 light years away from Earth.   Bob travels in a rocket at 80% of the speed of light, and at the moment he leaves Earth, the star is only 4.8 light years while he travels towards it at this speed.

How far away does the star look?

The three possibilities offered are: My initial assumption was been that because space is contracted to 60% for Bob, that the star would look like it is that distance away, 4.8 light years.   There is no argument that the distance really is less (it doesn't just seem or look less), because what he sees as a straight line to the star is actually a shorter curved geodesic path than the geodesic path he sees at rest. Using the logic that light reaches earth from the star 'equally', regardless of the speed of objects at the earth, then observers both on earth and next to the earth in a fast moving rocket will see the star to be the same distance, 8 light years away, just as they see the same time on the star clock. Paul Alan Cardinale has offered some formulas which show that the star looks 24 light years away.   Paul has checked his formulas and posted them on science newsgroups for discussion. I think we all agree that Bob will reach the star in 6 of his years (not Earth years), so both (2) and (3) imply that it must appear to him that he approaches the star at greater than the speed of light.   Of course, judging speed is even harder than judging distances, and I have very little idea of what this would really look like. If you would like to add your considered opinion, or refute any of the above, please email me. Many thanks all so far, GM Arts

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